English Opening, Anglo-Dutch Defense

The Anglo-Dutch Defense arises after White advances the c-pawn to c4 and Black answers with ...f5. The pawn on f5 controls e4, making it harder for White to build an easy pawn center there. Black commonly follows with quick development, such as a knight on f6 and preparations for ...g6 or ...e6.

The move ...f5 gains space, but it also has a cost. The pawn that originally helped shelter the king has left f7, and it no longer guards e6 and g6. This does not make Black's position unsafe automatically, but Black must coordinate the pieces before launching an attack.

The setup resembles a Dutch Defense, but it is not the same opening. White's c-pawn is already on c4, while the d-pawn can still choose d3, d4, or remain unmoved. That difference changes the central struggle and creates English Opening plans. Compared with a quieter reply such as the Agincourt Defense, ...f5 declares Black's intentions much earlier.